JP7205499B2 - Thermal insulation member for roll shaft of continuous annealing furnace and continuous annealing furnace - Google Patents

Description

The present invention relates to a heat insulating member for the roll shaft portion of a continuous annealing furnace. It relates to a roll shaft heat insulating member for preventing the heat from reaching the inside of the furnace along the roll shaft. The present invention also relates to a continuous annealing furnace having this roll shaft heat insulating member.

A continuous annealing furnace is a furnace in which a coiled steel sheet is successively received in a furnace in a reducing atmosphere and continuously annealed while being conveyed by conveying rolls (hearth rolls). As described in Patent Document 1, both ends in the longitudinal direction (roll axis direction) of the roll that conveys the steel plate extend out of the furnace through roll insertion holes provided in the furnace wall, and are rotatably supported by bearings. It is Between the furnace body and the bearings, a cylindrical member for preventing outflow of gas in the furnace is provided so as to surround the end of the roll. A lubricant such as grease is supplied to the bearing.

Conventionally, ceramic fibers, which have excellent properties as a lightweight refractory material and a heat insulating material, have been used for furnace linings in continuous annealing equipment and the like (for example, Patent Document 2). Ceramic fibers are produced by fiberizing a ceramic material in a high-temperature molten state by a spinning method using centrifugal force or a blowing method in which high-speed compressed air is blown away. The ceramic fibers contain non-fibrous particles, ie shots, which remain in the form of particles that cannot be completely turned into fibers, and these shots cause dust.

JP 2006-170254 A Japanese Patent Application Laid-Open No. 2006-10107

Since the temperature of the continuous annealing furnace is raised to a high temperature (for example, 1000°C), the high-temperature furnace gas enters the bearing through the gap between the end of the hearth roll and the roll insertion hole, and the heat causes the grease to evaporate. Alternatively, the grease leaks from the roll bearings due to the high-temperature gas in the furnace, reaches the furnace along the roll shaft, and is carbonized in the furnace. As a result, soot scatters in the furnace and adheres to the conveyed steel sheet, causing surface defects such as non-plating in the subsequent plating process (Patent Document 1, paragraph 0005). In addition, the energy for heating the steel plate is taken up by the soot, and there is a problem that the heating efficiency deteriorates.

Patent Document 1 describes that a seal disc is provided to prevent intrusion of gas in the furnace to the bearing, but details of the constituent material of the seal disc are not described.

The present invention provides roll shaft insulation for preventing the heat of high-temperature gas in the furnace of a continuous annealing furnace from being transferred to the bearings and/or preventing lubricant leaking from the roll bearings from reaching the furnace along the roll shaft. It is an object of the present invention to provide a member and a continuous annealing furnace equipped with this roll shaft heat insulating member.

The gist of the present invention is as follows.

[1] A roll shaft heat insulating member installed between a roll insertion hole and a roll bearing of a continuous annealing furnace,
Having an inorganic fiber blanket having a shot content of 3% or less of 45 μm or more in contact with or close to the outer peripheral surface of the roll, and having a residual thickness of 70% or more after the 1000° C. cycle test of the inorganic fiber blanket. A roll shaft heat insulating member for a continuous annealing furnace, characterized by:

[2] The roll shaft heat insulating member for a continuous annealing furnace according to [1], wherein the inorganic blanket has a maximum load of 5.0 kgf or more under the following measurement conditions.
[Measurement condition]
For an inorganic blanket sample (length 210 mm, width 80 mm), a penetrating part was created using a cork borer (inner diameter 14 mm) at a position of 40 mm from the tip in the center in the horizontal direction, and a rod with an inner diameter of 12 mm was inserted into the penetrating part. After fixing the horizontal end face farther from the penetration part, the bar is raised in the longitudinal direction of the sample while keeping it horizontal, and the breaking load (maximum load) is measured.

[3] The heat insulating member for the roll shaft portion of the continuous annealing furnace according to [1], wherein the inorganic fiber blanket is an alumina fiber blanket.

[4] The roll shaft heat insulating member for a continuous annealing furnace according to [2], wherein the alumina fibers constituting the alumina fiber blanket have a mullite crystallinity of 85% or less.

[5] The roll shaft heat insulating member has a casing having a drum portion surrounding the outer peripheral surface of the roll coupled with the furnace wall or the roll bearing support member, and the inorganic fiber blanket is placed inside the drum portion of the casing. A roll shaft heat insulating member for a continuous annealing furnace according to any one of [1] to [4], which is held along the peripheral surface.

[6] The roll shaft of the continuous annealing furnace according to [5], wherein the inorganic fiber blanket is ring-shaped, and a plurality of ring-shaped inorganic fiber blankets coaxially stacked and arranged are attached to the casing. Part heat insulation member.

[7] The inorganic fiber blanket is plate-shaped, and a plurality of inorganic fiber blankets are arranged in a circumferential direction along the inner peripheral surface of the drum portion with each plate surface parallel to the axial direction of the drum portion. has been
The roll shaft heat insulating member for a continuous annealing furnace according to [6], wherein the casing has a tightening mechanism for adjusting the distance between the roll shaft and the roll shaft heat insulating member.

[8] A continuous annealing furnace provided with the roll shaft heat insulating member according to any one of [1] to [7].

A roll shaft heat insulating member having an inorganic fiber blanket having a shot content of 45 μm or more of 3% or less and a remaining thickness of 70% or more after a cycle test at 1000° C. is installed between the roll insertion hole and the roll. By doing so, it is possible to prevent heat from entering the furnace. As a result, the temperature rise of the bearing is suppressed, and soot generation due to grease carbonization is prevented. As a result, surface defects such as non-plating can be prevented, and the frequency of cleaning work inside the furnace for removing accumulated soot can be reduced.

In addition, since an inorganic fiber blanket having a shot content of 45 μm or more and a shot content of 3% or less is used as a material for the roll shaft heat insulating member, particulate foreign matter derived from the inorganic fiber blanket is not mixed in the furnace, and the steel sheet and the roll are affected. It is preferable because it does not cause scratches due to foreign matter, and even if the roll shaft is rotated while it is in contact with the roll shaft portion heat shielding member, it is only polished and does not cause a large scratch, and the roll shaft does not deteriorate. preferable. By using an inorganic fiber blanket with a remaining thickness of 70% or more after a cycle test at 1000 ° C., the dimensions are less likely to change due to movement such as roll shaft vibration under high temperature conditions, and as a result, the roll and the heat insulating member This is preferable in that gaps are less likely to occur.

In addition, when soot enters the furnace, the energy required to heat the steel plate is lost by the soot.

It is a longitudinal cross-sectional view near the roll shaft portion of the continuous annealing furnace according to the embodiment. It is a longitudinal cross-sectional view near the roll shaft portion of the continuous annealing furnace according to the embodiment. It is a longitudinal cross-sectional view near the roll shaft portion of the continuous annealing furnace according to the embodiment. It is a longitudinal cross-sectional view of the roll shaft portion heat insulating member according to the embodiment. 5 is an enlarged view of a portion of FIG. 4; FIG. 1 is a front view of a roll shaft heat insulating member according to an embodiment; FIG. 7 is a cross-sectional view taken along line VII-VII of FIG. 6; FIG. FIG. 8 is a perspective view showing the middle of manufacturing the roll shaft heat insulating member of FIGS. 6 and 7; FIG. 8 is a perspective view showing the middle of manufacturing the roll shaft heat insulating member of FIGS. 6 and 7;

Embodiments will be described below with reference to the drawings. FIG. 1 shows a vertical cross-sectional view of the vicinity of the roll shaft portion of a continuous annealing furnace 1 according to the first embodiment.

A continuous annealing furnace 1 is provided with a large number of horizontally arranged rolls 2 for conveying steel sheets to be treated. The roll 2 has a large-diameter portion 2a with the same diameter, and roll shaft portions 2b on both end sides of the large-diameter portion 2a. The roll shaft portion 2b has a tapered portion 2c whose diameter gradually decreases from the large-diameter portion 2a toward both ends, and equal-diameter portions 2d, 2e, and 2f on both end sides of the tapered portion. The diameters of the equal diameter portions 2d, 2e, and 2f decrease in this order. The equal diameter portion 2f is supported by the roll support member 4 via the bearing 3. As shown in FIG. Grease is supplied to the bearing 3 through an injection pipe (not shown).

The roll support member 4 has a first plate 4a facing the furnace body 1, a second plate 4b perpendicular to the first plate 4a, and a bearing holding housing 4c. A roll insertion opening 4d is provided in the first plate.

A furnace body side wall 10 of the continuous annealing furnace 1 has a steel shell 11 and a ceramic fiber liner 12 provided inside the steel shell 11 .

A liner block 20 is attached to an opening 13 provided in the side wall 10 of the furnace body. The liner block 20 has an iron shell 21 and a ceramic fiber liner 22 provided inside the iron shell 21 in the furnace. A roll insertion hole 23 is provided so as to pass through the liner 22 and the steel shell 21 . A seat plate 21a made of an annular iron plate is fixed to the periphery of the roll insertion hole 23 of the steel shell 21 .

The roll insertion hole 23 has a tapered shape in which the inner side of the furnace has a larger diameter, and the outer side of the furnace is a cylindrical hole of equal diameter. The roll shaft portion 2b extends out of the furnace through the roll insertion hole 23. As shown in FIG.

A cylindrical cover 30 is provided so as to surround the portion of the roll shaft portion 2b that extends from the roll insertion hole 23 to the outside of the furnace. This cylindrical cover 30 is in the shape of a bellows that can be expanded and contracted in the axial direction of the cylinder. A first flange 31 provided on one end side of the cylindrical cover 30 is attached to the first plate 4a of the roll support member 4 with bolts, nuts, or the like.

A second flange 32 provided on the other end side of the cover 30 is attached to the seat plate 21a of the steel shell 21 with bolts and nuts. In this embodiment, the flange portion 41b of the roll shaft heat insulating member 40 is sandwiched between the second flange 32 and the seat plate 21a.

In this embodiment, as shown in FIGS. 4 and 5, the roll shaft heat insulating member 40 has a casing 41, an inorganic fiber blanket 42 held by the casing 41, and the like. The casing 41 includes a cylindrical drum portion 41a, a flange portion 41b projecting radially (outwardly) from one end of the drum portion 41a, and an inner portion projecting inwardly from one end of the drum portion 41a in the cylinder axis direction. and a pressing ring 43 detachably attached with a screw or the like to the other end of the drum portion 41a in the cylinder axis direction.

A bolt (not shown) is inserted through a bolt insertion hole 41d provided in the flange portion 41b. The bolt is also inserted through a bolt insertion hole (not shown) provided in the second flange 32 of the cylindrical cover 30 and the seat plate 21a of the steel shell 21, and a nut is screwed thereon. As a result, the flange portion 41 b is sandwiched between the second flange 32 and the seat plate 21 a , and the roll shaft portion heat insulating member 40 is fixed to the liner block 20 .

The inorganic fiber blanket 42 is in the form of a ring-shaped (annular) disc in this embodiment. A plurality of inorganic fiber blankets 42 are coaxially superimposed and stitched together by alumina fiber ropes 47 to form an inorganic fiber blanket laminate 48 . One end face of the inorganic fiber blanket laminate 48 in the lamination direction is overlapped with the collar portion 41 c , and the outer peripheral edge of the other end face is pressed by the pressing ring 43 . As a result, the inorganic fiber blanket laminate 48 is held by the casing 41 .

The inorganic fiber blankets 42 are superimposed so that their inner peripheral surfaces 42a are coaxially aligned, and the inorganic fiber blanket laminate 48 has a cylindrical inner hole 48a. A monolithic refractory such as mortar may be adhered between the inorganic fiber blankets 42 to form a monolithic refractory layer. By having a monolithic refractory layer between each inorganic fiber blanket 42, the bonding strength between each inorganic fiber blanket 42 is increased, and the grease volatilized outside the furnace or the soot generated outside the furnace It is preferable in terms of preventing intrusion into. Also, a shielding layer such as a metal plate may be provided between each inorganic fiber blanket 42 . Having a shielding layer between the inorganic fiber blankets 42 is preferable in that it prevents grease volatilized outside the furnace or soot generated outside the furnace from entering the furnace.

The roll shaft portion 2b is inserted through the inner hole 48a of the inorganic fiber blanket laminate 48. As shown in FIG. The inner peripheral surface of the inner hole 48a is elastically pressed against the outer peripheral surface of the roll shaft portion 2b (small diameter portion 2c in this embodiment).

In the continuous annealing furnace 1 having the roll shaft heat insulating member 40 configured in this way, even if the high temperature gas in the furnace enters the roll shaft portion insertion hole 23, the roll shaft heat insulating member 40 Further entry into the bearing 3 side is prevented. Therefore, the temperature rise of the bearing 3 is suppressed, and the vaporization and carbonization of the grease are prevented.

Even if part of the gas in the furnace enters the cover 30 side of the roll shaft heat insulating member 40, the amount is small and the heat is radiated from the cover 30 for cooling, so the temperature rise of the bearing 3 is suppressed. be done.

Further, by providing the roll shaft heat insulating member 40, even if the vaporized grease enters the cover 30 from the bearing 3, the roll shaft heat insulating member 40 prevents it from further entering the inside of the furnace. Therefore, formation of grease carbide in the furnace is prevented. In addition, since the roll shaft heat insulating member 40 absorbs the liquefied grease that enters along the rolls, the formation of grease carbide is prevented.

In FIG. 1, the drum portion 41a of the roll shaft heat insulating member 40 is arranged in the furnace inside direction than the flange portion 41b, but as shown in FIG. may

Further, in the present invention, the roll shaft heat insulating member 40 may be attached to the first plate 4a of the roll support member 4 as shown in FIG.

Other configurations in FIGS. 2 and 3 are the same as in FIG. 1, and the same reference numerals denote the same parts.

4 and 5, the plate surface of the inorganic fiber blanket 42 is perpendicular to the axis of the inner hole 48a, but the present invention is not limited to this. For example, in the present invention, the plate surface of the inorganic fiber blanket 42' may be parallel to the axis of the drum portion 41a, as in the roll shaft heat insulating member 40' shown in FIGS.

6 to 9, the inorganic fiber blanket 42' has a square plate shape and is laminated in the circumferential direction of the inner peripheral surface of the drum portion 41a. Each inorganic fiber blanket 42' is thicker on the outer peripheral side than on the inner peripheral side. The superimposed inorganic fiber blankets 42' are bound and integrated with ropes 47 of alumina fibers to form a cylindrical inorganic fiber blanket laminate 48'.

As shown in FIG. 9, an inorganic fiber sheet 49 is wound around the outer circumference of this cylindrical inorganic fiber blanket laminate 48', and a tightening band 50 is wound around the outer circumference. Both ends of this tightening band 50 are inserted through the slots (long holes) of the tightening rod 51 . By rotating the tightening rod 51 around its axis as indicated by arrow R, both ends of the tightening band 50 are wound around the rod 51 and the inorganic fiber blanket laminate 48' is tightened by the tightening band 50. As a result, when the hearth roll is displaced due to expansion/contraction, it can follow the tightening, and the gap between the roll shaft and the roll shaft portion heat shielding member can be minimized. The inorganic fiber sheet 49 is folded back and overlaid on the outer peripheral side of the tightening band 50 .

This inorganic fiber blanket laminate 48' is also held in the casing 41 in the same manner as the inorganic fiber blanket laminate 48, as shown in FIGS. As shown in FIG. 7, the tightening rod 51 is bridged between the collar 41c of the casing 41 and the pressing ring 43. As shown in FIG.

Other configurations in FIGS. 6 to 9 are similar to those in FIGS. 4 and 5, and the same reference numerals denote the same parts.

In the above description, the inner peripheral surfaces of the inner holes 48a of the inorganic fiber blanket laminates 48, 48' are in contact with the outer peripheral surface of the roll shaft portion 2b. There may be a slight clearance (preferably 10 mm or less, more preferably 5 mm or less, particularly preferably 3 mm or less) between the surfaces.

In the present invention, the inorganic fiber blanket is preferably an alumina fiber blanket. Next, an alumina fiber blanket having a shot content of 45 μm or less suitable for use in the present invention of 3% or less and a residual thickness of 70% or more after a 1000° C. cycle test of the inorganic fiber blanket will be described.

In the continuous annealing furnace, it is preferable that there is no particulate foreign matter of 45 μm or more that affects steel plate scratches. The shot content of 45 μm or more contained in the alumina fiber blanket is measured using a 325 mesh 45 μm shot content in accordance with JIS R3311 (nominal size of 212 μm of sieve JIS Z 8801) contained in ceramic fiber blanket. Measure using a sieve.

The alumina fiber blanket used in the present invention preferably does not substantially contain fibers having a fiber diameter of 3 μm or less and is subjected to a needling treatment. The use of this needle blanket is also preferable from the standpoint of load resistance. Here, "substantially free of fibers with a fiber diameter of 3 μm or less" means that the fibers with a fiber diameter of 3 μm or less account for 0.1 wt % or less of the total fiber weight.

The average fiber diameter of alumina fibers constituting the alumina fiber blanket used in the present invention is preferably 5 to 7 μm. If the average fiber diameter of the alumina fibers is too large, the repulsive force and toughness of the blanket will be lost. Become.

The alumina/silica composition ratio (wt%) of the alumina fibers constituting the alumina fiber blanket used in the present invention is preferably in the range of 65 to 98/35 to 2, more preferably 68 to 85/32 to 15. more preferably 70-80/30-20, particularly preferably 70-76/30-24. In addition, the mullite crystal ratio of the alumina fibers constituting the alumina fiber blanket used in the present invention (ratio of mullite (3Al ₂ O ₃ .2SiO ₂ ) in the alumina fibers) is not particularly limited, but is usually 85% or less, It is preferably 75% or less, more preferably 60% or less, even more preferably 30% or less, even more preferably 20% or less, and particularly preferably 10% or less. The mullite crystallinity is measured as follows. The measurement sample was pulverized in a mortar and measured with an X-ray diffractometer (for example, manufactured by RIGAKU) at a voltage of 30 kv, a current of 40 mA, and a speed of 4°/min. Read the peak height h. In addition, under the same conditions, a standard product (for example, mullite standard material (Japan Ceramics Association certified standard material JCRM-R041) or alumina fiber (alumina: silica = 72:28, mullite crystal ratio 65 to 75%) at 1500 ° C. for 8 hours Heat treated fibers, etc.) are measured and the peak height h ₀ at 2θ=26.3° is read. The mullite crystallinity at this time is a value represented by the following formula.
Mullite crystallinity = h/h ₀

By setting the mullite crystal ratio within the above range, it is preferable in that it is possible to achieve a balance between heat insulating properties, workability, and cushioning properties.

An example of such an alumina fiber blanket is Maftec (registered trademark) manufactured by Mitsubishi Chemical Corporation.

The thickness of the alumina fiber blanket used in the present invention is preferably 6-25 mm, more preferably 7-13 mm. This alumina fiber blanket preferably has a shrinkage rate of less than 1% (measuring method is based on JIS R3311) under the conditions of heating at 5°C/min and holding at 1500°C for 8 hours.

The basis weight of the alumina fiber blanket used in the present invention is preferably 1000-3000 g/m ² , more preferably 1200-2800 g/m ² , particularly preferably 1400-2500 g/m ² .

In the present invention, the inorganic fiber blanket such as an alumina fiber blanket has a residual thickness of 70% or more, preferably 75% or more, more preferably 80% after a 1000 ° C. cycle test in the measurement method described below. Above, more preferably 85% or more, particularly preferably 90% or more, particularly preferably 96% or more.

Measurement method: A sample prepared by cutting a plurality of inorganic blankets into pieces of 10 mm long and 50 mm wide, arranged so as to expose the cut end surface of the sample, sewn the sample with alumina thread, and integrated sample (45 mm long x wide 50 mm x height 10 mm). After compressing the sample at a height of 8.25 mm for 30 minutes, the upper and lower plates were heated to 1000 ° C. and compressed from a height of 9.5 mm (open side) to a height of 7 mm (compression side). repeat times. The residual thickness before and after the measurement is calculated as a ratio (%) of the thickness of the inorganic fiber blanket after measurement to the thickness of the inorganic fiber blanket before measurement.

When the remaining thickness is within the above range, the repulsive force of the inorganic fiber blanket is maintained even when vibrations generated during the operation of the furnace are applied, and the inner peripheral surface of the inner hole 48a of the inorganic fiber blanket laminate 48, 48' There is no gap between the outer peripheral surfaces of the roll shafts, and outflow of gas in the furnace is sufficiently prevented.

As the alumina fiber blanket used in the present invention, an alumina fiber needle blanket is preferable because the alumina fiber blanket is less likely to be peeled off.

The density of needle marks in the alumina fiber needle blanket used in the present invention, that is, the number of needle marks per unit area (1 cm ² ) of the mat surface, is preferably 1.0 to 50.0 needle marks/cm ² as an average value of the entire mat surface. is 15.0 to 40.0/cm ² , particularly preferably 20.0 to 35.0/cm ² . The method of calculating the needle mark is to cut a square of 50×50 mm into a sample, irradiate visible light from one side of the sample, and point the shadow of the needle mark projected on the other side with a magic pen. The needle mark density is calculated by counting the number of points.

The inorganic fiber blanket such as the alumina fiber blanket used in the present invention preferably has a maximum load of 5.0 kgf or more, more preferably 6.5 kgf or more, still more preferably 8.0 kgf or more, under the following measurement conditions. Particularly preferably, it is 8.5 kgf or more. When the maximum load of the inorganic fiber blanket is within the above range, it is preferable in that it has durability against an external force such as axial vibration of the roll, and as a result, a gap between the roll and the roll shaft heat insulating member is less likely to occur.

[Measurement condition]
For an inorganic blanket sample (length 210 mm, width 80 mm), a penetrating part was created using a cork borer (inner diameter 14 mm) at a position of 40 mm from the tip in the center in the horizontal direction, and a rod with an inner diameter of 12 mm was inserted into the penetrating part. After fixing the horizontal end face farther from the penetration part, the bar is raised in the longitudinal direction of the sample while keeping it horizontal, and the breaking load (maximum load) is measured.

The inorganic fiber blanket such as the alumina fiber blanket used in the present invention preferably has a lubricant absorption height of 9.5 mm or less, more preferably 8.5 mm or less, and particularly preferably 8.5 mm or less under the following measurement conditions. 0 mm or less. When the lubricant absorption height of the inorganic fiber blanket is within the above range, the lubricant leaking from the roll bearings is gradually absorbed, which is preferable in that less lubricant enters the furnace.

[Measurement condition]
A sample of an inorganic fiber blanket with a length of 120 mm and a width of 20 mm was immersed in a lubricant (manufactured by Azet, model number ISOVG68) for 90 seconds with the sample end surface being 20 mm below the liquid surface. After recovery, the lubricant was absorbed from the soaked end surface. Measure the distance to the top of your position.

The above-described embodiment is an example of the present invention, and the present invention may be in a form other than the above.

<Measurement method>
[Remaining thickness after 1000°C cycle test]
A sample prepared by cutting a plurality of inorganic blankets into pieces of 10 mm long and 50 mm wide is prepared, arranged so that the cut end surface of the sample is exposed, and sewn with alumina thread to integrate the sample (45 mm long × 50 mm wide × high 10 mm) was fabricated. After compressing the sample at a height of 8.25 mm for 30 minutes, the upper and lower plates were heated to 1000 ° C. and compressed from a height of 9.5 mm (open side) to a height of 7 mm (compression side). repeated times. The residual thickness before and after the measurement was calculated as a ratio (%) of the thickness of the inorganic fiber blanket after measurement to the thickness of the inorganic fiber blanket before measurement.

[Measurement of mullite crystal ratio]
The measurement sample was pulverized in a mortar and measured with an X-ray diffractometer (manufactured by RIGAKU) at a voltage of 30 kv, a current of 40 mA, and a rate of 4 ° / min, and the peak of 2θ = 26.3 °, which is the peak of mullite. Height h was read. In addition, a standard product is a fiber obtained by heat-treating alumina fiber derived from an alumina fiber blanket (alumina: silica = 72:28, mullite crystal ratio 68%, Maftec (registered trademark), manufactured by Mitsubishi Chemical Corporation) at 1500 ° C. for 8 hours. was measured under the same conditions as the measurement sample, and the peak height h ₀ at 2θ=26.3° was read. The mullite crystallinity at this time is a value represented by the following formula.

Mullite crystallinity = h/h ₀

[Inorganic fiber blanket maximum load]
For an inorganic blanket sample (length 210 mm, width 80 mm), a penetrating part was created using a cork borer (inner diameter 14 mm) at a position of 40 mm from the tip in the center in the horizontal direction, and a rod with an inner diameter of 12 mm was inserted into the penetrating part. After fixing the horizontal end face farther from the through-hole, the bar was raised in the longitudinal direction of the sample while keeping it horizontal, and the breaking load (maximum load) was measured.

[Lubricant absorption height]
A sample of an inorganic fiber blanket with a length of 120 mm and a width of 20 mm was immersed in a lubricant (manufactured by Azet, model number ISOVG68) for 90 seconds with the sample end surface being 20 mm below the liquid surface. After recovery, the lubricant was absorbed from the soaked end surface. I measured the distance to the top of the position where I was doing it.

[Example 1]
Alumina fiber blanket 1 (trade name: Maftec (registered trademark), manufactured by Mitsubishi Chemical Corporation, alumina: silica = 72:28, mullite crystal ratio 1.5%, basis weight 1500 g/m ² ) was measured according to the above-described measurement method. Measured based on Table 1 shows the results.

[Example 2]
Alumina fiber blanket 2 (trade name: Maftec (registered trademark), manufactured by Mitsubishi Chemical Corporation, alumina: silica = 72:28, mullite crystal ratio 70.8%, basis weight 1600 g / m ² ), according to the above-described measurement method Measured based on Table 1 shows the results.

[Example 3]
Alumina fiber blanket 3 (alumina:silica=80:20, mullite crystal ratio: 50.0%, basis weight: 1600 g/m ² ) was measured based on the measurement method described above. Table 1 shows the results.

[Comparative Example 1]
Amorphous fiber blanket 3 (alumina:silica:zirconia=35.5:49:15, basis weight: 2000 g/m ² ) was measured based on the measurement method described above. Table 1 shows the results. Since the fibers of the silica fiber blanket 3 are amorphous fibers, the mullite crystallinity could not be measured.

Although the present invention has been described in detail using specific embodiments, it will be apparent to those skilled in the art that various modifications can be made without departing from the spirit and scope of the invention.
This application is based on Japanese Patent Application 2018-019476 filed on February 6, 2018, the entirety of which is incorporated by reference.

1 Continuous Annealing Furnace 2 Roll 2b Roll Shaft Part 3 Bearing 4 Roll Supporting Member 10 Furnace Body 20 Liner Block 21 Iron Shell 21a Seat Plate 22 Ceramic Fiber Liner 23 Roll Insertion Hole 30 Cylindrical Cover 31, 32 Flange 40 Roll Shaft Heat Insulating Member 41 casing 41a drum portion 41b flange portion 41c collar portion 42 inorganic fiber blanket 43 holding ring 48, 48' inorganic fiber blanket laminate 50 tightening band 51 tightening rod

Claims (5)

A roll shaft heat insulating member installed between a roll insertion hole and a roll bearing of a continuous annealing furnace,
Having an inorganic fiber blanket having a shot content of 3% or less of 45 μm or more in contact with or close to the outer peripheral surface of the roll, and a remaining thickness of the inorganic fiber blanket after a 1000° C. cycle test of 70% or more . ,
The roll shaft heat insulating member has a casing having a drum portion surrounding the outer peripheral surface of the roll coupled with the furnace wall or the roll bearing support member, and the inorganic fiber blanket is placed on the inner peripheral surface of the drum portion of the casing. is held along
The inorganic fiber blanket is plate-shaped, and a plurality of inorganic fiber blankets are arranged in a circumferential direction along the inner peripheral surface of the drum portion with each plate surface parallel to the axial direction of the drum portion. ,
A roll shaft heat insulating member for a continuous annealing furnace , wherein the casing has a tightening mechanism for adjusting the distance between the roll shaft and the roll shaft heat insulating member. 2. The heat insulating member for the roll shaft portion of the continuous annealing furnace according to claim 1, wherein the inorganic fiber blanket has a maximum load of 5.0 kgf or more under the following measurement conditions.
[Measurement condition]
For an inorganic fiber blanket sample (length 210 mm, width 80 mm), a penetrating part was created using a cork borer (inner diameter 14 mm) at a position 40 mm from the tip at the center in the horizontal direction, and a bar with an inner diameter of 12 mm was placed in the penetrating part. After fixing the horizontal end face farther from the penetration part, the bar is raised in the longitudinal direction of the sample while keeping it horizontal, and the breaking load (maximum load) is measured. 2. The roll shaft heat insulating member for a continuous annealing furnace according to claim 1, wherein said inorganic fiber blanket is an alumina fiber blanket. 4. The roll shaft heat insulating member for a continuous annealing furnace according to claim 3 , wherein the alumina fibers constituting said alumina fiber blanket have a mullite crystal percentage of 85% or less. A continuous annealing furnace comprising the roll shaft heat insulating member according to any one of claims 1 to 4 .

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